Establishment of a Carcinoembryonic Antigen Stable Cell Line for Cancer Immunotherapy Study

Introduction: Cancer immunotherapy is one of the effective treatment methods that provide a better quality of life with limited side effects for patients. Carcinoembryonic Antigen (CEA) can be an appropriate target for cancer immunotherapy. Methods: A lentivector expressing CEA antigen, pCDH-CEA, was constructed by cloning CEA cDNA downstream of the CMV promoter. The constructed plasmid was co-transfected with helper plasmids, into Lenti-X 293 T cells. The lentivector-containing supernatant was collected. Titers of the CEA- lentivector were estimated using the RT-PCR method. The CT26 cells were then infected by CEA- lentivector. Puromycin as a selective antibiotic was added to the culture for 2 weeks to select CEA-positive cells. The ability to produce tumors in BALB/c mice was investigated. Results: The results showed that CEA expressing lentivector plasmids and the two other helper plasmids could be transfected into Lenti-X 293T cells efficiently and packaged successfully as a pseudo-lentivector. The detection of CEA mRNA and protein expression in the 6th and 14th passages of CT26-CEA cells was confirmed in the engineered stable cell line. Tumor formation was confirmed in cell inoculated mice. Conclusion: CT26-CEA cell line with stable expression of CEA can be used as a suitable tumor model to facilitate research on colorectal cancer in vitro and in mice models; therefore, it could be served as a valuable tool for cancer immunotherapy.